Quiz 8 Flashcards
(35 cards)
Bone Cement Implantation Syndrome
- Hypoxia (increased pulmonary shunt)
- Hypotension
- Dysrhythmias (heart block and sinus arrest)
- Pulmonary htn (increased PVR)
- Decreased Cardiac Output
- Embolization most frequent during prosthetic insertion
Strategies to minimize effects of MMA
-Increase inspired O2 prior to mma
-Maintain euvolemia
-Vasopressor as needed
Surgical methods:
-venting distal femur
-high pressure lavage of femoral shaft
Prolonged cuff time 45-60 min associated with:
- htn
- tachycardia
- sympathetic stimulation (sweating)
Cuff deflation drops ___ and ___ (and pain). ___ increases, ________ decreases
CVP
MAP
HR
core temp
which fibers are responsible for tourniquet pain
C fibers (slow conduction)
Metabolic Changes after cuff deflation
Increase:
- PaCO2
- ETCO2
- lactate
- potassium
Decreased:
- PaO2
- pH
- See increase in minute volume in spont breathing pt and possibly dysrhythmias
- Reperfusion injuries from free radical formation
Fat Embolism Syndrome
-Classic presentation w/in 72 h of long bone or pelvic Fx
Triad of:
- dyspnea
- confusion
- petechiae
Also seen with CPR, liposuction, IV lipids
Pathogenesis: fat globules released by disrupted fat cells in fx bone and enter circulation through tears in _________________
medullary vessel
Fat embolism syndrome diagnosis
- Petechiae
- Fat globules - retina, urine, sputum
- Coagulation abnl: thrombocytopenia, prolonged clotting time sometimes seen
- Progressive pulm involvement from mild hypoxia and clear CXR to ARDS
- Under GETA see decline in ETCO2 and SPO2 and rise in PAP (peak airway pressures)
- Treatment is supportive. Early stabilization is key to prevention.
Deep Venous Thrombosis and PE risk factors (including highest)
-post pelvic and lower extremity surgery
Risk factors:
- age > 60yr
- obesity
- tournique
- procedures >30 min
- lower extremity fx
- immobilzation > 4 days
-Highest risk are in knee and hip replacements
Role of Neuraxial Anesthesia in less chance of DVT
- Sympathectomy induced increases in venous blood flow
- Antiinflammatory effects of local anesthesia
- Decreased platelet activity
- Decreased rise in factor VIII and Von Willebrand factor
- Less fall in antithrombin III
- Less stress hormone release
______ itself is not a contraindication to neuraxial anesthesia.
Aspirin
Placement of epidural needle or catheter (or removal) should not be undertaken within ____ h of a SQ minidose of heparin or within _____ h of LMWH
6-8
12-24
________ anesthesia associated with lower risk of hematoma than ________ anesthesia
Spinal
epidural
Hallmarks of hematoma from spinal/epidural are _____________ and __________________
back pain
lower extremity weakness
Selection of Anesthesia:
Regional
- Pt with multiple medical problems
- Pt with full stomach
General
- May need rapid sequence induction
- If remote, mask or LMA maybe okay
Hip Fracture Predictors of peri-op mortality (5):
- Age >85 yrs
- H/o cancer
- Baseline/pre-op alteration in neuro status
- Post-op chest infection
- Post-op wound infection
Hip Fracture: Benefits of regional anesthesia
- Reduced blood loss
- Reduced dvt / pe (advantage over general)
- Quicker return to baseline neuro
Will lose benefit of regional if…
- Pt oversedated
- Pt is allowed to become hypoxic
- After two months, no difference in mortality for regional vs general
Hip fracture: Minimize postop cognitive impairment
-Minimize use of midazolam in older pt Maintain: -oxygenation -hemoglobin -normocapnea
THA intraop management: Embolic event most frequent at ___________________________
insertion of femoral component
THA intraop: Blood Loss
400-1500 ml, 2000 ml for revisions
TOTAL KNEE ARTHROPLASTY TKA: EBL
EBL less intraop (100-200 ml) as limited by tourniquet
Highest rate of dvt of all ortho procedures
TKA
TKA: Less bone cement syndrome than hip, but release of emboli w/tourniquet deflation may increase __________
hypotension (Check BP after tourniquet goes down)
